LongitudinalStudyofBovin Mastitisin Hawassa and WendoGenetSmall HolderDairyFarms

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1 Global Journal of Science Frontier Research: D Agriculture and Veterinary Volume 14 Issue 2 Version 1.0 Year 2014 Type : Double Blind Peer Reviewed International Research Journal Publisher: Global Journals Inc. (USA) Online ISSN: & Print ISSN: Longitudinal Study of Bovine Mastitis in Hawassa and Wendo Genet Small Holder Dairy Farms By Fentaye Kassa, Alemu Aylate Ayano, Mesele Abera & Ashenafi Kiros Wolaita Sodo University, Ethiopia Abstract- A longitudinal study was carried out to determine the prevalence and incidence of mastitis in lactating dairy cows from November 10, 2011 to June 25, 2012 in six purposively selected smallholder dairy farms in Hawassa and Wendo- Genet districts, Ethiopia. The study was carried out through field screening surveys by California mastitis test for each quarter milk sample, followed by retesting negatives group for mastitis twice a month during the study period to estimate the incidence of mastitis. At the time bacteriological examinations to identify the causative agents from mastitis positive cows were carried out. A total of 122 milking cows were examined, out of which 77 (63.1%) and 152 (31.1%) were found positive for mastitis on the basis of California mastitis test at cow and quarter level, respectively. Out of the total quarters examined, 25 (5.12%) were recorded as a blind teats. The incidences of mastitis were seen to be 0.49 in three month study period. Slight variations in incidence rate between different farms were revealed. Higher incidence rate of 0.54 was recorded in cows kept in bad concrete in comparison to cows kept in good concrete which is On the other hand, higher incidence rate was recorded in single and three or above parity; in early and late stage of lactation. Keywords: bovine mastitis, prevalence, incidence, hawassa, wendo-genet, major pathogens. GJSFR-D Classification : FOR Code: LongitudinalStudyofBovin Mastitisin Hawassa and WendoGenetSmall HolderDairyFarms Strictly as per the compliance and regulations of : By Fentaye Kassa, Alemu Aylate Ayano, Mesele Abera & Ashenafi Kiros. This is a research/review paper, distributed under the terms of the Creative Commons Attribution-Noncommercial 3.0 Unported License org/licenses/by-nc/3.0/), permitting all non commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

2 Longitudinal Study of Bovine Mastitis in Hawassa and Wendo Genet Small Holder Dairy Farms Fentaye Kassa α, Alemu Aylate Ayano σ, Mesele Abera ρ & Ashenafi Kiros Ѡ Abstract- A longitudinal study was carried out to determine the prevalence and incidence of mastitis in lactating dairy cows from November 10, 2011 to June 25, 2012 in six purposively selected smallholder dairy farms in Hawassa and Wendo- Genet districts, Ethiopia. The study was carried out through field screening surveys by California mastitis test for each quarter milk sample, followed by retesting negatives group for mastitis twice a month during the study period to estimate the incidence of mastitis. At the time bacteriological examinations to identify the causative agents from mastitis positive cows were carried out. A total of 122 milking cows were examined, out of which 77 (63.1%) and 152 (31.1%) were found positive for mastitis on the basis of California mastitis test at cow and quarter level, respectively. Out of the total quarters examined, 25 (5.12%) were recorded as a blind teats. The incidences of mastitis were seen to be 0.49 in three month study period. Slight variations in incidence rate between different farms were revealed. Higher incidence rate of 0.54 was recorded in cows kept in bad concrete in comparison to cows kept in good concrete which is On the other hand, higher incidence rate was recorded in single and three or above parity; in early and late stage of lactation. Proportion of bacterial isolates isolated from mastitis cows showed high proportion of Staphylococcus species (52.9%) followed by Streptococcus species (23.5%), Bacillus species (9.8%), E. coli (7.8%) and Corynebacterium species (5.9%). It was concluded that there was a higher incidence and prevalence of mastitis, mainly caused by Staphylococcus species and Streptococcus species. Based on the findings, recommendations were made accordingly to concerned organs. Keywords: bovine mastitis, prevalence, incidence, hawassa, wendo-genet, major pathogens. I. Introduction E thiopia is believed to have the largest livestock population in Africa. This livestock sector has been contributing considerable portion to the economy of the country, and still promising to rally round the economic development of the country. It is eminent that livestock products and by-products in the form of meat, milk, honey, eggs, cheese, and butter supply provide mainly the needed animal protein that contributes to the improvement of the nutritional status Author α σ Ѡ : School of Veterinary Medicine, Wolaita Sodo University, Wolaita Sodo, Ethiopia. ayanoalemu@yahoo.com Author ρ: School of Veterinary Medicine, Hawassa University, Hawassa, Ethiopia. of the people. The total livestock population for the country is estimated to be 50.8 million cattle, 25.9 million sheep, 21.9 million goats, 1.9 million horses, 5 million donkeys, 0.3 million mules, 0.8 million camels and the total poultry population at country level is estimated to be about 42 million (CSA, 2009). In Southern Nations Nationalities and People Regional States (SNNPRS), the total cattle population is estimated at about 8.8 million. Nearly all the cattle population (98.41%) is found in rural areas while a small proportion (1.59%) is found in urban areas (CSA, 2003). Even though Ethiopia is the most populous country in cattle than any African country; up to 1997 the per Capita milk consumption was 16 kg, which was lower than other countries in the region (Asfaw, 1997). This is partly due to the low genetic milk production potential of the indigenous zebu cattle. To increase milk production cross breeding of indigenous zebu with exotic breeds particularly with Holstein Friesian is widely practiced in the country which resulted in a larger portion of the dairy cattle population especially in urban areas to be with a high level of exotic blood. However, this market oriented dairy production, a rapidly growing system in many African countries, is subjected to diseases of intensification including mastitis and reproductive disorders (Lemma et al., 2001). Ethiopia holds large potential for dairy development due to its large cattle population and the favorable climate for improved high yielding animal breeds (Bishi, 1998). Considering the potential if smallholder income and employment generation, development of dairy farming can make significant contribution to the poverty reduction and nutritional improvement in the country (Staal, 1996). Given the considerable potential for income and employment generation from high value dairy product (Bishi, 1998). Dairy production is a biological efficient system that converts large quantities of roughage which is the most abundant of fed to milk (Reugg, 2001). In Ethiopia where access to market dairying is preferred to meet production since it makes more efficient use of feed resource and provides a regular income to the produces. Milk is very nutritional food that is reach in carbohydrate, protein, fat, vitamin and minerals. The increase in human populations, accessibility to technology input and high demand for animal product Global Journal of Science Frontier Research ( D ) Volume XIV Issue II V ersion I Year

3 D Year Global Journal of Science Frontier Research ( ) Volume XIV Issue II V ersion I purchasing power in urban center had helped the urban and per-urban dairy farm in the country to flourish (Yoseph et al., 1998). Mastitis is one of the most important disease affecting dairy cows. It is a multi-factorial disease with worldwide distribution accounting for major economic losses in dairy cattle (DeGrave and Fetrow, 1993) which incurs serious economic losses to dairy industry. A number of previous reports from different part of the country indicated that mastitis is a serious problem in the dairy industry of Ethiopia (Bishi, 1998). Bovine mastitis can reduce milk yield, increase culling rate, incur treatment cost, occasionally result in death from sever infection (Radostitis et al., 2007). Mastitis had been known to cause a great deal of loss or reduction of productivity, to influence the quality and quantity of milk yield, and to cause culling of animals at an unacceptable age (Singh and sigh, 1994). Most estimates have shown a 30% reduction in productivity per affected quarter and a 15% reduction in production per cow per lactation (Radostits et al., 1994). The disease generally involves interplay between management practice and infection agent. Among various infectious agents, bacterial pathogens have been known to be widely distributed in the environment of dairy cows, constituting threat to the mammary gland (Schalm et al., 1989). Mastitis is a management related disease whose prevention and control depends among other factors on the type of management employed. If management is improved; there is a reduction in the incidence of clinical mastitis and vice versa. As with most infectious disease, mastitis risk factors depends on three components i.e. exposure to the microbes, cow defense mechanism, and environment and management factors (Suriyasathaporn et al., 2000). Therefore, the objectives of this study were: To estimate the prevalence and the incidence of mastitis in the study area To isolate major pathogen and to identify the associated risk factors II. Materials and Methods a) Study Area The study was carried out in small holder dairy farms in Hawassa and Wendo-genet. Hawassa which is the capital town of SNNPRS is located at 275 km South of Addis Ababa. It lies geographically between 4o27, and 8o 30, latitude North and 34o 21, and 39o 1, East longitude. The annual rain fall and temperature varies from mm and oC, respectively. Wondo-genet is located 264 km from Addis Ababa and 30 km from Hawassa (SZPEDD, 2001). b) Study Population The study population constitutes of lactating government and private owned cross breed cows found in Hawassa and Wendo-Genet small holder dairy farms. Cows are kept in exclusive stalls and provided with supplementary diets in addition to the pasture and agricultural by-products. c) Study Design The study was a longitudinal observational study in which all the study animals were tested at the beginning of the study period for clinical and subclinical mastitis by physical examination of the udder and by CMT (California Mastitis Test), respectively. Each farm was visited for three consequetive months at two weeks interval and screening of CMT negative cows was done throughout the study period using California Mastitis Test (CMT) to detect the presence of new cases of mastitis. Information regarding the potential risk factors for both clinical and sub clinical mastitis such as age, parity, stage of lactation, udder injury, frequency of milking, tick infestation and hygiene of the farm were collected. To identify the major bacterial pathogens milk samples were collected from mastitic cows and subjected to bacteriological examination. d) Sample Size and Sampling Method From both study sites a total of 122 animals from the target population were first tested for mastitis and those negative for mastitis at the first screening was followed and checked in two weeks interval during the study period and those positive for CMT removed from the study and recorded as new case. e) Sample Collection and Laboratory Analysis i. Physical Examination of the Udder and Milk The udder was first examined visually and then palpated to detect possible fibrosis, inflammatory swelling, and atrophy of the tissue. The size and consistency of the mammary quarter were inspected for the presence of any abnormalities such as disproportional symmetry, swelling, firmness, and blindness. In addition milk from each quarter was inspected by visual inspection for presence of any flakes, clots and color change. f) California Mastitis Test Every two weeks after a visit to the farm all lactating dairy cows, which are negative for subclinical mastitis at the first visit, were tested with CMT during the study period. Subclinical mastitis was diagnosed based on CMT result and the nature of coagulation and viscosity of the mixture, which show the presence, and the severity of the infection respectively (Radostits et al., 1994). CMT grades were evaluated and the results graded as 0 and 1 for negative and 2 and 3 for positive (Kerro Dego and Tareke, 2003). Then milk sample was collected from CMT positive cows for bacteriological examination.

4 g) Milk Collection The udder of the animal was thoroughly cleaned with water (Chauhan and Argawal, 2006). The teat orifice was also cleaned using cotton soaked in 70% ethyl alcohol (Quinn et al., 1999). After discarding a few streams of milk, by holding the sterile collection bottle nearly horizontal, about 3 to 4 ml milk was collected (NMC, 1990). Then the samples were labeled and transported in ice-packed cool box to microbiology laboratory of the school of Veterinary Medicine, Hawassa University. h) Bacteriological Examination of Milk Sample In the laboratory a loopful of the milk samples were streaked on to the blood agar base enriched with 7% sheep blood and MacConkey agar. The plates were incubated at 37oC aerobically and examined after 18 to 24 hours for the presence of fast growing organism and then returned to the incubator for at least another 24 hours and reexamined (NMC, 1990). Identification of the bacteria isolate was done according to NMC (1990) and Quinn et al (2002) Colony morphology, Gram staining, catalase test, motility test, triple sugar iron reaction, CAMP test, IMViC (Indole, Methyl red, Voges-Proskauer, Citrate) and coagulase test were conducted to identify the isolates. Farm Name III. Statistical Analysis a) Result From the total 122 lactating cows examined for mastitis, prevalence of 63.1% (77) and 31.1% (152) were recorded at cow level and quarter level, respectively. The prevalence at each farm levels is shown in Table 1. From 77 mastitis positive cows 33 (42.9%), 19 (24.7%), 19 (24.7%) and 6 (7.8%) cows had one, two, three and four quarters infection respectively (Table 2). Out of the total 488 quarter examined 25 (5.1%) quarters were blind out of which 3.2% (5/156), 4.2% (3/72), 5.3% (4/76), 2.1% (1/48) and 10.7% (12/112) from HU, SOS, Biniyam, Saron and Wendo- Genet but no blind teat in Eden farm ( Table 3). Out of 45 lactating cows intially at risk for mastitis 22 (48.9%) cows had mastitis in three months period of follow up and the incidence risk of 42.9%, 33.3%, 75.0%, 50.0% and 50.0% were recorded for HU, SOS, Biniyam, Saron and Wendo-Genet farm respectively but no new infection recorded in Eden farm (Table 4). The incidence risk (IR) and the relative risk (RR) of different risk factors is shown in Table 5. Among 51 bacterial isolates, Staphylococcus species and Streptococcus species were the dominant isolates. The relative isolation rate of Staphlococcus species was 52.9% (27), Streptococcus species 23.5% (12), that of E. coli 7.8% (4), Bacillus species 9.8% (5) and Corynebacterium species 5.9% (3) (Table 6). Table 1 : The Prevalence of Subclinical Mastits at Cows Level and Quarter Level No. of cows examined No. of CMT positive cows Prevalence (%) No. of quarters examined No. of quarters affected HU farm SOS Biniyam Saron Eden Wendo Genet Total % Global Journal of Science Frontier Research ( D ) Volume XIV Issue II V ersion I Year

5 Table 2 : The Proportion of Quarters Affected from Mastitis Positive Cows D Year Global Journal of Science Frontier Research ( ) Volume XIV Issue II V ersion I Farm Name No. of quarters affected & prevalence 1 % 2 % 3 % 4 % Total % HU farm SOS Biniyam Saron Eden Wendo Genet Total Table 3 : The Prevalence of Blind Teat in Different Farms Farm Name No. of quarters examined No. of blind teat (%) HU farm SOS Biniyam Saron Eden Wendo Genet Total Table 4 : Incidence Risk of Mastitis in the Study Farms from December, 2011 to April 2012 Farm Name No. of animals initially at risk No. of animals affected Incidence Risk (%) HU farm SOS Biniyam Saron Eden Wendo Genet Total

6 Table 5 : The Incidence Risk and Relative Risk of Mastitis in Association with Selected Risk Factors during the Study Period (December, 2011 to April, 2012) Risk factors Floor type No. of animals initially at risk No. of animals affected Incidence Risk (%) Good concrete Bad concrete Age < 5 yrs > 5yrs Parity Single Two and above Stage of Lactation Relative Risk Early Mid Late IV. Table 6 : Proportion of Bacteria Isolated from Mastitis Positive Cows Bacterial isolates No. of isolates Staphylococcus spp Streptococcus spp Corynebacterium spp E. coli Bacillus spp Total Discussion The result of this study showed the prevalence of mastitis in Hawassa and Wendo-genet town to be 63.11% at cows level and 31.15% at quarter level, which is in agreement with the report of Biru (1989) in Ethiopia (63%), Workineh et al (2002) in two major Ethiopian dairies (59.7%), Tolla (1996) in South Wollo (61.11%) and Byarugaba et al (2008) in Uganda (61.3%). However, it was higher than the report of Fekadu (1995) in Caffa valley in Northern Ethiopia (39.65%), Biffa et al (2005) in Southern Ethiopia (34.9%), Kerro Dego and Tareke (2003) in Southern Ethiopia (40.40%), but lower than the report of Mekibib et al (2010) in Holeta town in Centeral Ethiopia (71.05%). The overall quarter prevalence of mastitis was 31.15%. This finding is comparable with the report of Sori et al (2005) which was (30.95%). However, this finding was higher than that of Vecht et al (1989) in the Netherland and Hoyer et al (1991) in Zimbabwe, who reported 10%, 14%, respectively. This variation in the prevalence of bovine mastitis between different reports could suggest the complexity of the disease which involve interaction of several factors, mainly management practice, husbandry system, environment and factors related to causative agent and variation in veterinary service coverage. Out of 488 quarter examined, 5.12% were blind, which may be an indication of serious mastitis problem on the herd and lack of screening tests and treatment of subclinical mastitis, and inadequate follow up chronic mastitis were considered to be the major reason for the development of quarter blindness (Biffa, 2005). In this study there was one cow with clinical mastitis but the rest of the cases were subclinical. This may be due to ease of detection of clinical mastitis and treatment of only clinical cases. Moreover absence of dry cow therapy in all farms might be the cause of higher prevalence of subclinical mastitis in the study area. The overall incidence risk mastits in the three months period of follow up is 0.49, this finding is in agreement with the report of Roy et al (1999) in India which had the incidence of This result was higher % Global Journal of Science Frontier Research ( D ) Volume XIV Issue II V ersion I Year

7 D Year Global Journal of Science Frontier Research ( ) Volume XIV Issue II V ersion I than the report of Bartlett et al (1991), Rajala et al (1999), Barkema et al (1998), Lucey et al (1996) which were 0.097, 0.18, 0.24 and respectively. In this study relatively higher incidence risk (0.75) was recorded in Binyam farm when compared with other farms. This might be due to improper washing of hands and teats before milking and use of one towel for each cow. According to Rice and Bodman (2004) sanitary milking habits are important to avoid the spreading of bacteria or their proliferation. The result of the present study also revealed higher incidence of mastitis (0.54) in cow kept under bad concrete as compared to cows kept in good concrete (0.41). The relative risk of mastitis in cows kept under bad concrete is 1.3 times higher than that cows kept in good concrete. This might be due to the favorable environment created for survival and multiplication of bacterial pathogens. In this study there were higher risk of mastitis in cows with single parity (0.60) and cows with more than two parity (0.64) when compared with cows with two parity (0.21). However studies conducted by Houben et al (1993), Lucey et al (1994) and Rajala et al (1999) showed incidence risk of 6.6%, 17%, 12.1% for parity one, 9.0%, 22%, 14.3% for parity two and 14.2%, 24%, 14.9% for parity three respectively. The finding of this study also showed higher incidence risk of mastitis in early (0.64) and late (0.50) stages of lactation as compared to mid (0.22) stage of lactation. The finding of higher incidence risk in early stage of lactation is in agreement with Barkema et al (1998). This increase in incidence risk of mastitis at early stage might be due to high milk yield at this stage of lactation (Bartlett et al., 1991; Grohn et al., 1995; Smith et al., 2000). The finding of higher proportion of Staphylococcus species (52.9%) from total isolates is in consistent with that of Wokineh et al (2002) who reported 57% of the total bacterial isolates. The finding of higher proportion of Staphylococcus species might be due to lack of effective udder washing and drying, post milking teat dip and drying and hand washing (Radostits et al.,1994). It is also attributed to the wide distribution of the bacteria on the skin of teats and udder (Mac Donald, 1997). The staphylococci have adapted to survive in the udder, they usually establish chronic, subclinical, infection and are shed in the milk which serves as a source of infection for other health cows during the milking process (Radostits et al., 1994). In this study Streptococcus species accounted for 23.5% of the total isolates next to Staphylococcus species. This finding was in agreement with Zerihun (1996) which was (27%), but lower than the report of Kingwill et al (1991) which was (80.95%), Tolosa (1987) (53.55%). The lower isolation rate of Streptococcus species might be due to wide spread use of penicillin in the area for the treatment of mastitis. The finding of E. coli in this study may be associated with poor hygienic condition in the farm, unimproved management, wet and muddy stall were cows are kept. V. Conclusion and Recommendation Generally, mastitis is one of the complex diseases of dairy cows which involve an interaction between management practice and infectious agent occurring throughout the world. The disease has also been reported in different parts of Ethiopia with varying prevalence. But incidence of mastitis in the country has not been studied like that of prevalence and the spreading of mastitis among cows was not determined. Inadequate hygienic condition of dairy cow s stalls, poor milking procedure, poor animal health service and lack of proper attention to the heath of the mammary gland were important for the high prevalence and incidence of mastitis in the study area. The present study showed that the occurrence of mastitis at cow and quarter level is high and the incidence of mastitis also high, which can interfere with efficiency of milk production and has high economic importance. From this study the most important pathogens causing mastitis in the study area was Staphylococcus species and Streptococcus species, which were isolated from the milk sample in higher proportion, which is associated with unhygienic milking practice and poor herd management, whereas the finding of other bacteria such as E. coli is associated with poor hygiene of the stall and bedding. Based on this study, to reduce the incidence risk of mastitis the following recommendations are forwarded: Standard milking procedure, such as pre and post milking udder washing should be applied to reduce the risk of transmission. Regular screening of subclinical mastitis for early detection and treatment, and culling of chronically infected cows should be practiced. Dry cow therapy should be applied to reduce the occurrence of new infection after parturition. Adequate housing with proper sanitation of the cow s barn and bedding to reduce environmental mastitis. To reduce the prevalence of the disease, different epidemiological factors that interplay in mastitis occurrence should be studied routinely. VI. Acknowledgements Authors would like to thank dairy farm owners in Hawassa and Wendo-Genet for their cooperation and School of Veterinary Medicine of Hawassa University for financial supports.

8 References Références Referencias 1. Abdelrahim, A. I., Shommein, A., Suliman, H. B., Shaddad, S. A. I. (1989): Prevalence of mastitis in imported Friesian cows in Sudan. Review of Production and Veterinary Medecine for tropical Country. 47, Andrews, A. H., Blowely, R. W., Hoyd, H., Eddy, R.G. (2004): Bovine Medicine and Husbandery of cattle 2nd ed. Blackwell Science Ltd, Blackwell Publishing Company. Pp Argaw, K. and Tolosa, T. (2005): The prevalence of sub clinical mastitis in small holder dairy farm in Selale, North Showa zone, central Ethiopia. The international J of Vet Med, Asfaw, W. (1997): Livestock development policy in Ethiopia. In: CTA, OAU/IBAR, Ministry of Agriculture and Cooperatives, Swaziland. Livestock Development Policies in Eastern and Southern Africa. Paper presented in a seminar held in Mbabane, Swaziland, 28 July August Banerjee, K., Ray, J. P., Sadhukhan, T., Das, R., Chandra, S. (2002): Studies on etiological agents of sub clinical mastitis in dairy cows in West Bengal. Ind. J. Ani. Hlth. 41: Barkema, H. W., Shukken, Y. H., Lamtj, G. M., Beiboer, M. L., Wilmilk, H., Benedictus, G. (1998): Incidence of clinical mastitis in dairy herds grouped in three categories by bulk milk somatic cell counts. J Dairy Sci 81: Bartlett, P. C., Vanwijk, J., Wilson, D. J., Green, C. D., Miller, G. Y., Majeweski, G. A., Heider, L. E. (1991): Temporal patterns of lost milk production following clinical mastitis in large Michigan Holstein herd. J Dairy Sci. 74: Becker, N. G. (1989): Analysis of infectious disease data. Chapman and Hall, London. 9. Biffa, D., Debela, E., Beyene, F. (2005): Factors Assocaited with Udder Infection in lactating dairy cows in southern Ethiopia. Praxis Veternaria 53 (3) Biru, G. (1989): Major bacteria causing bovine mastitis and their sensativity to common antibiotic. Ethiopia Journal of Agricultur Science. 11: Bishi, A.S. (1998): Cross-sectional and longitudinal prospective study of bovine clinical and subclinical mastitis in peri-urban and urban dairy production systems in the Addis Ababa region, Ethiopia, Msc Thesis, Faculty of Veterinary Medicine, Addis Ababa University School of Graduate Studies and Freie Universidad, Berlin. 12. Bramely, A. J. (1992): Mastitis in disease and husbandry of cattle. U. K, Blackwell scientific publication, pp Byarugaba, D. K., Nakavuma, J. L., Vaarst, M., Laker, C. (2008): Mastitis occurance and constraints to mastitis control in smallholder dairy farming system in Uganda. Livestock Resarch for rular development. 20: Central Statistical Agency (CSA) (2009): Federal Democratc Republic of Ethiopia Centeral Stastical Agency (CSA): Agricultural Sample Survey. Livestock and livestock Characteristics vol, Central Statistical Authority (CSA) (2003): Statistical Report of Socio-Economical characteristics of the Population in Agriculture Household and land Use: Results for SNNP Region Volume 2, part 1, Addis Ababa, Ethiopia. 16. Chauhan, R. S, and Agarwal, D. K, (2006): Text book of Veterinary Clinical & Laboratory Diagnosis, 2nd ed. India, JAPEEBROTHERS, pp DeGrave, F. J. and Fetrow, J. (1993): Economics of mastitis and mastitis control. Veterinary Clinics of North America. Food Animal Practice. 9: Doane, R. M., Oliver, S. P., Walker, S.D., Shull, E. P. (1987): Experimental infection of lactating bovine mammary glands with Streptococcus uberis in quarters colonized by Corynebacterium bovis. American J. Vet. Res. 48: Erskine, R. J., Eberhart, R. J., Hutchinson, L. J., Spencer, S.B. (1988): Incidence and types of clinical mastitis in dairy herds with high and low somatic cell counts. Journal of the American Veterinary Medical Association. 192: Fekadu, K. (1995): Survey on the prevalence of Bovine Mastitis and predominant causative agent in Chaffa vally. Page In: proceeding of the 9th conference of Ethiopia Veterinary Association, Addis Ababa, Ethiopia. 21. Fourichon, C., Seegers, H., Beaudeau, F., Verfaille, L., Bareille, N. (2011): Health control cost in dairy farming system in Westarn France. 68: Grohn, Y. T., Eicker, S. W., Hertl, J. A. (1995): The association between previous 305-day milk yield and disease in New York state dairy cows. J Dairy Sci. 78: Hirsh, D. C. and Zee, Y. C. (1999): Veterinary Microbiology. USA, Black well science, Inc. pp Hogan, J. S., Gonzalez, R. N., Harmon, R. J., Nickerson, S. C., Oliver, S. P., Pankey, J. W., Smith, K.L. (1999): Laboratory and field handbook on bovine mastitis. Madison, WI, National Mastitis Council, Inc, pp Houben, E. H. P., Dlijkhuizen, A. A., Van Arendonk, J. A. M., Huirne, R.B.M. (1993): Short- and long-term production losses and repeatability of clinical mastitis in dairy cattle. J Dairy Sci. 76: Hoyer, M. J., Codd, R., Bishi, A. S., Pawandiwa, A., Usenic, E. A. (1991): The prevalence of clinical mastitis in the beef herd in Zembabwe. Zembabwe Veterinary Jourinal. 22: 1. Global Journal of Science Frontier Research ( D ) Volume XIV Issue II V ersion I Year

9 D Year Global Journal of Science Frontier Research ( ) Volume XIV Issue II V ersion I 27. Huber, W.G. (1994): Antibacterial drug effectiveness against pathogens. Journal of the American Veterinary Medical Association. 170: Hussein, N., Yehualashet, T., Tilahun, G. (1997): Prevalence of mastitis in different local and exotic breeds of milking cows. Ethiopian Journal of Agricultural Science. 16: Jain, N.C. (1987): Common mammary pathogen and factor in infection and mastitis. J Dairy Sci. 190: Jones, G. M., Bailey, T. L., Roberson, J. R. (1998): Staphylococcus aureus mastitis: Cause, Detection, and Control. Virginia State University, Jones, T. C., Hunt, R. D., King, N. W. (1996): Veterinary pathology, 6th ed LIPPINCOTWILLIAM &WILIKING, pp Jubb, K. V. F., Kennedy, P. C., Palmer, N. (1993): Pathology of Domestic Animals, 4th ed, vol 3,USA Elsevier Science, pp Kassa, T., Wirtu, G., Tegegne, A. (1999): Survey of mastitis in dairy herds in the Ethiopian central highlands. Ethiopian Journal of Science. 22: Kerro Dego, O. and Tareke, F. (2003): Bovine mastitis in selected area of southern Ethiopia. Journa of tropical Animal Health and Production. 35: Kingwill, K. G., Nealce, F. K., Dodd, F. H., Griffin, T. K., Westgarth, D. R., Wilson, C. D. (1991): The effect of mastitis control system on the level of subclinical and clinical mastitis in two years, Vet Rec. 87: Kossaibati, M. A., Hovi, M., Esslemont, R. J. (1998): Incidence of clinical mastitis in dairy herds in England. Veterinary Recored. 143: Lemma. M., Kassa, T. Tegegene, A. (2001): Clinically manifested major health problems of crossbred dairy herds in urban and periurban production systems in the central high lands of Ethiopia. Journal of Tropical Animal Health and Production. 33: Lucy, S., Rowlands, G. J., Russell, A. M. (1996): Short-term associations between disease and milk yield of dairy cows. J Dairy Res. 53: MacDonad, J. S. (1997): Streptococcus and Staphylococuss mastitis. Journal of the American Veterinary Medical Association. 170: Mekibib, B., Fergasa, M., Abunna, F., Megersa, B., Regassa, A. (2010): Bovine Mastitis: Prevalance, Risk factors and major pathoges in Dairy farms of Holeta town, Centeral Ethiopia. Vet. World. 3: Mohammed, A. (2010): Bacterial cause mastitis in Wondo-Genet, Ethiopia. Journal of Veterinary Medicine. 43: Mungube, E. O. Tenhagen, B. A., Regassa, F., Kyule, M. N., Shiferaw, Y., Kassa, T., Baumann, M. P. (2005): Reduced Milk Production in Udder Quarters with Sub clinical Mastitis and Associated Economic Losses in Crossbred Dairy Cows in Ethiopia. Journal of Tropical Animal Health and Production. 37: NMC (1990): Microbiological procedure for the diagnosis of bovine udder infection. 3rd ed. Arlington V A: National Mastitis Council, Inc. 44. Quinn, O. K., Carter, M.E., Markey, B., Carter, G.R. (1999): Clinical Veterinary Microbiology. USA, Elsevier Limited. 45. Quinn, P. J., Markey, B.K., Carter, M.E., Donnelly, W.J., Leonard, F.C. (2002): Veterinary Microbiology and Microbial Disease. Blackwell Science Ltd, Blackwell Publishing Campany. pp Radostits, O. M., Gay, C. C., Hinchcliff, K. W., Constable, P. D. (2007): Veterinary Medicine: A text book of the disease of cattle, horses, sheep, pigs and goats. 10th ed Elsevier London, pp Radostits, O. M., Leslie, K.E., Fetrow, J. (1994): Mastitis control in dairy herds. Herd Health Food Animal Production Medicine, 2nd ed. W. B. saunders, Philadelphia, pp Rajala, P. J., Grohn, Y.T., Mcculloche, C. E., Guard, C.L. (1999): Effects of clinical mastitis on milk yield in dairy cows. J Dairy Sci. 82: Reugg, L.P. (2001): Health and production management in dairy herds. In: Radostits, O.M. (ed), herd health, food animal production. 3rd ed. W. B. Saunders Company, Philadelphia, Pennsylvania, Pp Rice, D. N. and Bodman, G. R. (2004): The somatic cell count and milk quality. American J. Vet. Res. 25: Roy, S. K., Paye, P. K., Maitra, D. N., Dattagupta, R., Mazumber, S. C. (1999):Mastitis in cross breeds in hot humid condition of West Bengal, India. Vet. J. 66: Schalm, D.W., Carrol, E. G., Jain, C. (1989): Bovine mastitis. Lea and Febiger: Philadelphia. pp Sears, P. M., Gonzalez, R. N., Wilson, D. J., Han, H. R. (1999): Procedures for Mastitis Diagnosis and Control. Vet Clin North Am Large Anim Pract. 9: Sidama Zone Planning and Economic Development Department (SZPEDD, 2001). 55. Singh, P.J. and Sigh, K.B. (1994): A study on economic loss due to mastitis in India. J Dairy Sci. 47: Smith, A., Westgarth, D.R., Jones, M. R., Neave, F.K., Dodd, F.H., Brander, G.C. (1997): Methods of reducing the incidence of udder infection in dry cows. Vet Rec. 81: Smith, J. W., Elylo, O., Chapa, M. A. (2000): Effect of region, herd size, and milk production on reasons cows leave the herd. J Dairy Sci. 83:

10 58. Sori, H., Zerihun, A., Abdicho, S. (2005): Dairy cattle mastitis in and around Sebeta. Intern J Appl Res Vet Med. 3: Staal, S.J. (1996): The Economic Impact of Public Policy on Smallholder Peri-urban Dairy Producer in and around Addis Ababa, Ethiopia Society of Animal Production (ESAP) Publication No 2. Addis Ababa, Ethiopia. 60. Suriyasathaporn, W., Schukken, Y. H., Nielsen, M., Brand, A. (2000): Low somatic cell count: a risk factor for subsequent clinical mastitis in dairy herd. J Dairy Sci. 83: Tolla, T. (1996): Bovine mastitis in indigenous Zebu and Borana Holestein crosses in Southern Wollo. Thesis, Debrezeit: Faculity of Veterinary Medecine, Addis Ababa Universty: Ethiopia. pp Tolosa, A. (1987): A Survey of Bovine Mastitis around Kallu Province. Thesis, Debrezeit: Faculty of Veterinary Medecine, Addis Ababa Uinversty: Ethiopia. Pp Tyler, J.W. (1992): Treatment of subclinical mastitis. Vet Food Anim Pract. 8, Vecht, U., Wisselink, H., Detizer, P.R. (1989): Dutch National Mastitis Survey. The effect of herd animal factors on somatic cell count. Netheland Milk and Dairy Journals. 43, Weiss, W.P., Hogan, J.S., Todhunter, D.A., Smith, K.L. (1997): The effect of vitamin E supplementation in diets with low concentration of selenium on mammary gland health of dairy cow. J.Dairy Sci. 80: Wilesmith, J.W., Francis, P.G., Wilson, C.D. (1996): Incidence of clinical mastitis in cohort of British dairy herds. Veterinary Recored, 188: Wilson, D.J., Gonzalze, R.N., Das, H.H. (1997): Bovine mastitis pathogens in New York and Pennsyluania: Prevalence and effect on somatic cell count and milk production. J. Dairy Sci. 80: Workineh, S., Bayleyegne, M., Mekonnen, H., Potgieter, L.N.D. (2002): Prevalence and etiology of mastitis in cows from two major Ethiopian dairies. Journal of Tropical Animal Health and Production, 34: Yoseph, M., Azage, T., Alemu, Y., Umunna, N.N. (1998): Reproductive management and reproductive performance of dairy herds in urban and peri-urban dairy production systems in Addis Ababa milk shed. In: proceeding of the 6th annual conference of Ethiopia Society of Animal Production (ESAP), Addis Ababa, Ethiopia, Zerihun, T. (1996): A Study on Bovine Subclinical Mastitis at Stela Dairy Farm. Thesis, Debrezeit: Faculty of Veterinary Medecine, Addis Ababa Uinversty: Ethiopia. Pp Global Journal of Science Frontier Research ( D ) Volume XIV Issue II V ersion I Year

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